They don’t. I just found this on the White House Web Site:
Dubya menu–Wednesday, April 7, 2004:
Breakfast:
Count Chocula (NOTE: be sure a new toy surprise is placed in the box each AM)
Blueberry Pop-Tarts
Egg-Nog
Lunch:
Happy Meal (with TWO toys)
Dinner:
Kraft Mac and Cheese (The CHEEZIEST)
Funyuns
Chocolate Milk (w/Krazy Straw)
Birthday Cake (NOTE: yes, even when it’s not his b-day)
Party Hats
At least, they want you to believe it was eggs. 
Hee, hee. You forgot those party things you blow on and they unfurl! 
btw: Anyone know what they are called?
I grew up in the 50s and 60s. Probably monthly at school, we had air raid drills in case of a Russian attack. Atomic weapons would make short work of an old brick school with wooden interiors, and it was, I think, reasonably obvious that a small city of 30,000 whose primary manufactures were paper-making machines, air-hydraulic brakes for railroad rolling stock, and clinical thermometers, with (at that time) an Army summer training reservation with a permanent detachment of about 200, would clearly be one of Russia’s top targets. Nonetheless, we practiced, in hopes that if the unthinkable did occur, there’d be a chance to save some of us.
When the national military headquarters is under the glide path for a nearby airport, it makes sense to me to have disaster preparedness plans in place for a potential crash; whatever your opinions of Bush, Rice, Cheney, & Co., it’s tin-hat territory to suggest that this relates to prior knowledge of kamikaze-airliner terrorist attacks. I’m confident that the AFB in Kansas (Offutt?) has tornado shelters in place; to suggest they built them because they are really expecting a Dinosaur Killer asteroid whose existence they’re keeping secret from the public is about on a part with the thesis here.
oh, add after clinical thermometers, “and scented cardboard pine tree cutouts for automobile rearview mirrors” … can’t forget them!